Author Topic: Weird mpg readings on the trip computer.  (Read 3400 times)

Offline Nino

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Re: Weird mpg readings on the trip computer.
« Reply #10 on: 04 August 2014, 19:06 »
In that Case Change your coolent tempature sensor :)

how would that make a difference to mpg  :huh:

and that mpg is between 70 and 80, i do get 40+ mpg if im driving at 60

A Faulty Coolent temp sensor can throw all kinds of MPG readings and cause bad MPG
VW Car history
Mk3 1.8 GL - Silver - 5 door
Mk4 1.8t - Silver - 3 door
Mk4 R32 - Black - 5 door
Mk5 GTi - Black - 5 door
Mk4 R32 - Deep Pearl Blue - 3 door
MK6 2.0 TDI - Graphite Blue - 5 door
MK7 GTD - Solid Black - 5 door
MK6 GTi Edition 35 - Candy White - 3 door

Offline MoMartin

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Re: Weird mpg readings on the trip computer.
« Reply #11 on: 04 August 2014, 20:33 »
so these cars are definitely meant to get 40+ then? because i mean 36mpg has always been my best really when doing a motorway run

the engine condition is good and the car isn't throwing any fault codes, but then again i have no idea if coolant temperature sensor would throw up any codes anyway.

edit - also wheres a decent place to buy a new sensor? as on ebay they are a few quid, but on gsf and ecp they are a tenner or more.
« Last Edit: 04 August 2014, 21:26 by MoMartin »

Offline Nino

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Re: Weird mpg readings on the trip computer.
« Reply #12 on: 04 August 2014, 22:15 »
so these cars are definitely meant to get 40+ then? because i mean 36mpg has always been my best really when doing a motorway run

the engine condition is good and the car isn't throwing any fault codes, but then again i have no idea if coolant temperature sensor would throw up any codes anyway.

edit - also wheres a decent place to buy a new sensor? as on ebay they are a few quid, but on gsf and ecp they are a tenner or more.

When I had my 1.8t on a 10+ mile run on a motorway, staying between 50-60 my car would easyly hit 42-46mpg bare in mind, every boost hose was replaced for silicone, I had the forge 007p, Ramair induction, Ko3s turbo, I serviced it ever 6k along with cleaning the thottle body and it had a new temp sensor, thermo, new coolent, and all the gaskets, injector seals, where replaced.

With where to buy one, there is only one place. VW it will set you back around £38 now but if you buy any other brand it WILL fail, you have been warned.
VW Car history
Mk3 1.8 GL - Silver - 5 door
Mk4 1.8t - Silver - 3 door
Mk4 R32 - Black - 5 door
Mk5 GTi - Black - 5 door
Mk4 R32 - Deep Pearl Blue - 3 door
MK6 2.0 TDI - Graphite Blue - 5 door
MK7 GTD - Solid Black - 5 door
MK6 GTi Edition 35 - Candy White - 3 door

Offline MoMartin

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Re: Weird mpg readings on the trip computer.
« Reply #13 on: 04 August 2014, 22:56 »
all my boost hoses are replaced with silicone hoses, and i have a pipercross panel filter, forge 007p, still have the k03 turbo :angry: and also the throttle body has recently been cleaned /it was serviced around 4k miles ago, no idea when it was last serviced before that because i only bought the car 5k miles ago

also been remapped by r-tech if that does make a difference to fuel economy

and is oem quality temperature sensor a definite no go then? because i mean a jump from a few quid up to £38 quid is huge for a tiny sensor.

Offline Nino

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Re: Weird mpg readings on the trip computer.
« Reply #14 on: 05 August 2014, 08:51 »
Buy cheap, buy twice.
VW Car history
Mk3 1.8 GL - Silver - 5 door
Mk4 1.8t - Silver - 3 door
Mk4 R32 - Black - 5 door
Mk5 GTi - Black - 5 door
Mk4 R32 - Deep Pearl Blue - 3 door
MK6 2.0 TDI - Graphite Blue - 5 door
MK7 GTD - Solid Black - 5 door
MK6 GTi Edition 35 - Candy White - 3 door

Offline Dalo Harkin

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Re: Weird mpg readings on the trip computer.
« Reply #15 on: 05 August 2014, 12:57 »
I have to agree on this, the temp sensor needs to be genuine IMHO
ARZ K03s, Oettinger Side Skirts, R32 front, Carbon stage 2, Forge 007p (yellow spring), Forge Actuator (yellow spring), Pipercross panel filter with DSG parts, N249 and N112 deleted, SAI deleted, Carbon canister deleted, Rear wiper deleted, Long Life turbo back custom exhaust with 200 cell sports cat, VR6/G60 clutch kit, Creation Motorsport TIP, Catch can, 'Wellycooler', K04 charge pipe, S3 ported inlet manifold - looks pretty standard on the outside though :)

Offline MoMartin

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Re: Weird mpg readings on the trip computer.
« Reply #16 on: 05 August 2014, 17:37 »
ah okay then, does anyone know the part number for it?

nevermind i think i found it - 059919501
« Last Edit: 05 August 2014, 18:07 by MoMartin »

Offline MoMartin

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Re: Weird mpg readings on the trip computer.
« Reply #17 on: 26 August 2014, 13:29 »
Changed the coolant temperature sensor today , and found that the old one i had in it was a cheap knock-off version, so that is almost certainly the problem, i will take it on a motorway run tomorrow to see if my overall mpg goes up though.

Offline Dalo Harkin

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Re: Weird mpg readings on the trip computer.
« Reply #18 on: 26 August 2014, 17:43 »
Always go genuine on this sensor, let us know how you get on  :wink:
ARZ K03s, Oettinger Side Skirts, R32 front, Carbon stage 2, Forge 007p (yellow spring), Forge Actuator (yellow spring), Pipercross panel filter with DSG parts, N249 and N112 deleted, SAI deleted, Carbon canister deleted, Rear wiper deleted, Long Life turbo back custom exhaust with 200 cell sports cat, VR6/G60 clutch kit, Creation Motorsport TIP, Catch can, 'Wellycooler', K04 charge pipe, S3 ported inlet manifold - looks pretty standard on the outside though :)

Offline MoMartin

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Re: Weird mpg readings on the trip computer.
« Reply #19 on: 27 August 2014, 15:40 »
yeah, thats what i did, the person who had my car before me just seemed to work on the look of the car, and not the actual engine haha.

also i took it out on a motorway run today, i averaged 57 mph overall, (going up to 75 whenever i can) over 55 miles of motorway , and i got a max of 37.7mpg which is an improvement, but its still not quite what i should be getting.

the strange thing is that on the live mpg feed, when i was doing 75 i would actually average 42 or so mpg, but it just seemed to drop hugely (to about 25mpg) with the slightest adjustment of the pedal.